Blind fasteners used in the aerospace and other industries have both a diameter and sleeve length in their respective designs. Some fastener designs are created to produce a large amount of clamp-up, wherein the fastener, when it is installed, pulls the two work pieces together making them as tight as the upset load required to install the fastener. Other fastener designs are created to produce a hole filling requirement, wherein the fastener, when it is installed, expands outward against the work piece hole in which it is positioned, thus having both clamp-up and hole fill characteristics.
This second type of fastener is normally referred to as a “wire draw” fastener and comprises an inner, plugging portion attached to the upper stem portion of the fastener and a sleeve portion that is designed to expand when the installation tool pulls the stem portion. During installation, the plugging portion is drawn into the sleeve portion, and the plugging portion is elongated (stretched) within the sleeve portion until the stem is captured within the sleeve portion and breaks away from the plugging portion.
Normal fastener installation tools have a stroke length between about 0.45 inches and about 0.75 inches, which can install most blind rivets and many wire draw blind fasteners. However, wire draw blind fasteners are in use now that have longer grips, such as a −06 or a −07 grip length (for extending through a workpiece that is 6/16=⅜ inch or 7/16 inch thick, respectively), and the normal installation tool's stroke length is insufficient to install the fastener with a single stroke.
It is undesirable to use multiple tool strokes to install fasteners, because the first stroke work hardens the fastener. Re-gripping the fastener stem with the installation tool and pulling a second time often causes the stem to break off with too short a length, resulting in an unacceptable installation. Special, long stroke tools must be employed for these wire draw fasteners in the longer grip ranges. However, these special tools are much larger and heavier than standard installation tools, in addition to being much more expensive.
Commercial production shops, such as aircraft industry production shops, are replacing air-driven installation tools, attached to air hoses, with cordless, battery-operated installation tools to eliminate the tripping hazard posed by the air hoses dragged along the floor. However, cordless tools do not normally operate as quickly as air-driven tools, requiring two to three times as long to install a fastener.
Thus, there is a need for an adapter for use with a standard installation tool that increases the stroke length to allow single-stroke installation of blind fasteners having long grips. There is also a need for an adapter that increases the speed and efficiency of fastener installation in both cordless and standard air-driven tools.